Channel estimation algorithm in a wireless communication system uses a set of known sequences to perform channel impulse response estimation, and is essential to such key technology as reception and detection, and transmission and preprocessing. An ideal channel estimation is the one having nothing to do with noise, reflecting its own characteristics of a wireless channel. The original channel estimation is the one obtained according to the channel estimation algorithm after the channel estimation sequence passes through the wireless channel and reaches a receiver, but before signal detection. Compared with the ideal channel estimation, the original channel estimation is affected by both interference and noise and has a certain estimation error, which will affect the performance of such algorithms as signal detection and transmission preprocessing. Therefore, a further postprocessing is required after the original channel estimation is obtained to suppress the interference and noise in the channel estimation result and reduce the estimation error.
In the conventional art of a channel estimation postprocessing process of a Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) system, the noise tap and small signal tap not exceeding the threshold in a user channel estimation window are removed by a fixed or an adaptive power threshold, so as to improve the channel estimation precision of the communication system. However, the defects that remain in the noise residuals in the channel estimation signal tap cannot be estimated and removed, resulting in a poor channel estimation precision.